Problem: Umaima has taken 6 tests and her average score so far is 84. If she gets 100, a perfect score, on the remaining 2 tests, what will her new average be?
Solution: If she gets 100 on the remaining tests, the sum of her scores will be $6 \cdot 84 + 2 \cdot 100 = 704$ Her overall average will then be $704 \div 8 = 88$.